PIN proteins perform a rate-limiting function in cellular auxin efflux

Science. 2006 May 12;312(5775):914-8. doi: 10.1126/science.1123542. Epub 2006 Apr 6.

Abstract

Intercellular flow of the phytohormone auxin underpins multiple developmental processes in plants. Plant-specific pin-formed (PIN) proteins and several phosphoglycoprotein (PGP) transporters are crucial factors in auxin transport-related development, yet the molecular function of PINs remains unknown. Here, we show that PINs mediate auxin efflux from mammalian and yeast cells without needing additional plant-specific factors. Conditional gain-of-function alleles and quantitative measurements of auxin accumulation in Arabidopsis and tobacco cultured cells revealed that the action of PINs in auxin efflux is distinct from PGP, rate-limiting, specific to auxins, and sensitive to auxin transport inhibitors. This suggests a direct involvement of PINs in catalyzing cellular auxin efflux.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • Arabidopsis / cytology
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Biological Transport
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Gravitropism
  • HeLa Cells
  • Humans
  • Indoleacetic Acids / metabolism*
  • Kinetics
  • Membrane Transport Proteins / genetics
  • Membrane Transport Proteins / metabolism*
  • Mutation
  • Naphthaleneacetic Acids / metabolism
  • Nicotiana
  • Phthalimides / pharmacology
  • Plant Roots / physiology
  • Saccharomyces cerevisiae / genetics
  • Transfection
  • Transformation, Genetic

Substances

  • ATP-Binding Cassette Transporters
  • ATPGP1 protein, Arabidopsis
  • Arabidopsis Proteins
  • Indoleacetic Acids
  • Membrane Transport Proteins
  • Naphthaleneacetic Acids
  • PIN1 protein, Arabidopsis
  • PIN2 protein, Arabidopsis
  • PIN4 protein, Arabidopsis
  • PIN7 protein, Arabidopsis
  • Phthalimides
  • alpha-naphthylphthalamic acid
  • 1-naphthaleneacetic acid